The two most carcinogenic types of human papillomavirus (HPV) types 16 and 18, are responsible for around 70% of cervical cancers, 85% of anal cancers, and a smaller proportion of other anogenital and oral cancers.1 Vaccines that target these two sexually transmitted HPV types have consistently shown high efficacy in preventing disease related to those specific HPV types in people who have not yet been exposed.2 3 4 5 6 In the linked study (doi:10.1136/bmj.e1401), which is a post hoc analysis of the main efficacy trials (FUTURE I and FUTURE II) of the quadrivalent HPV vaccine that also targets non-carcinogenic HPV types 6 and 11 (responsible for most genital warts),2 3 Joura and colleagues show a reduction in subsequent HPV related disease in vaccinated women who received treatment for cervical, vulvar, or vaginal disease (including genital warts) during the course of the trial.7 This protection extended to disease associated with not only the four HPV types targeted by the vaccine but also 10 other HPV types that cause cancer.

The study’s findings—including reductions in any HPV related disease (irrespective of causal HPV type) of 46.2% after cervical surgery and 35.2% after diagnosis of vulvar or vaginal disease—are welcome, but some important caveats …

Setting Primary care centres and university or hospital associated health centres in 24 countries and territories around the world.

Participants Among 17 622 women aged 15–26 years who underwent 1:1 randomisation to vaccine or placebo, 2054 received cervical surgery or were diagnosed with genital warts, vulvar intraepithelial neoplasia, or vaginal intraepithelial neoplasia.

Intervention Three doses of quadrivalent HPV vaccine or placebo at day 1, month 2, and month 6.

Main outcome measures Incidence of HPV related disease from 60 days after treatment or diagnosis, expressed as the number of women with an end point per 100 person years at risk.

Results A total of 587 vaccine and 763 placebo recipients underwent cervical surgery. The incidence of any subsequent HPV related disease was 6.6 and 12.2 in vaccine and placebo recipients respectively (46.2% reduction (95% confidence interval 22.5% to 63.2%) with vaccination). Vaccination was associated with a significant reduction in risk of any subsequent high grade disease of the cervix by 64.9% (20.1% to 86.3%). A total of 229 vaccine recipients and 475 placebo recipients were diagnosed with genital warts, vulvar intraepithelial neoplasia, or vaginal intraepithelial neoplasia, and the incidence of any subsequent HPV related disease was 20.1 and 31.0 in vaccine and placebo recipients respectively (35.2% reduction (13.8% to 51.8%)).

Conclusions Previous vaccination with quadrivalent HPV vaccine among women who had surgical treatment for HPV related disease significantly reduced the incidence of subsequent HPV related disease, including high grade disease.